Robeet gnehm and jakob schmid



l NITED STATES PATENT FFICE.

ROBERT GNEIIM AND JAKOB SCHMID, OF BASLE, SWITZERLAND, ASSIGNORS TO THE SOCIETY OF CHEMICAL INDUSTRY, OF SAME PLACE.

GRAY COLORINGQMALTTER,

srncrrrcerron forming part of Letters Patent No. 413,050, dated October 15,1889..

Application filed May 16, 1889. Serial No, 3ll,O42| (Specimens) Patented in France April 18, 1888, No. 190,067-

,Zo all whom it may concern.-

Be it known that we, ROBERT GNEHM and J AKOB SoHMID, citizens of Switzerland, residing at Basle, in the Canton of Basle, Switzen 5 land, have invented new and useful Improvements in Gray Coloring-Matters, (for which Letters Patent have been granted to us in France, bearing date April 18, 1888, No. 190,067,) of which the following is a specification.

This invention is based on the discovery that metaoxydiphenylarnine, which was first described by V. Merz and W. lVeith,(Berichte cler cleutschen chcmischcn Gesellschaf, XIV,

r 5 1881, page 2,345,) when transformed into a phenylized derivative of meta-amidophenolphthaleine, produces coloring-matters which have the same relation to the ordinary metaamidophenolphthaleine as the rosaniline blue has to fuchsine.

The gray coloring-matter which forms the subject-matter of our present application for a patent is produced by the reaction of tetrachlorophthalic acid on metaoxydiphenylamine in the presence of chloride of zinc or another condensing agent at a temperature of from 180 to 210 centigrade.

In carrying out our inventionwe can proceed as follows: Seven kilograms of metaoxyo diphenylamine, six kilograms of tetrachlo rophthalic acid, and eight kilograms of chloride of zinc are mixed together and heated during five hours at a temperature of from 180 to 210 centigrade. The molten mass, Which is at first semtfluid, soon becomes solid. The glass-like melt, when cold, is finely pulver O C L MN 1 0,11, 5 0,01, 8 NEG/6H,

What we claim as new, and desire to secure 5 5 by Letters Patent, is-

As a new product, the gray coloring-matter or dyestuff, phenylnieta-amidophenoltetrachlorphthaleine, which forms a dark-green powder insoluble in water, difficultly soluble in hot alcohol, still more difiicultly soluble in benzine, and which dyes silk with a gray color, showing a strong fluorescence.

In testimony whereof we have hereunto set our hands and seals in the presence of two subscribing witnesses. 1

ROBERT GNEHM. JAKOB SCHMID.

[n s] [n s.) Witnesses:

GEORGE GIFFORD,

ED. BRAsELMANN. 

